Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to a plug made of plastic
and which is utilized for anchoring ob~ects flush or in spaced
relationship in a support structure, for example of concrete.
Plastic plugs of the type under consideration have an
elongated bore which receives a fastening screw, an expansible
portion which is anchored in a concrete structure, by screwing
in of that fastening screw, and an elongated neck which can have
ribs to secure the anchored plug against rotation.
Plugs having elongated necks are normally used for
secùring objects such as frames and battens to a support structure .
wherein the elongated neck engages the object to be secured. The
function of the elongated neck is to guide the fastening screw
in the plug and to fill the annular gap between the shaft of the
fastening screw and the wall of the drilled hole in the object
to be secured. In addition, the elongated neck may serve as a
bridge for ~oid places and in flush mountings to ensure suffici- i
ent anchoring depths, especially in porous building materials
such as foam concrete and the like.
Greater anchoring depths can lead to an increase in
puIl-out force values if the cause of failure is that the anchor-
ing base breaks away.
Anchoring plugs of the foregoing type have been dis-
closed in numerous U.S. patents of the inventor, for example U.S.
Patents 094,054; 4,149,350, etc.
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It is an object of the present invention to provide an ¦
improved anchoring plug.
It is another object of the invention to provide an
anchorin~ plug,the elongated neck of which would have greater
pull-out values in flush mounkings of the objects, especially in
porous building materials, and which would also allow a spaced
mounting of objects at void places.
These and other objects of the invention are attained
by a plastic anchoring plug for anchoring ob~ects in support
structures, comprising a body having a longitudinal bore; and a
fastening screw which is received in said bore for fastening an
object to a support structure, said body including an expansible
portion expanded and anchored in a hole of the support structure
when said screw is inserted into said bore, a base portion con-
nected to said expansible portion at one end thereof, and an
elongated neck connected to said expansible portion at another
end thereof and having a head provided with a flange and ribs to
secure said neck against rotation in said hole, said elongated
neck being formed by two expansible legs spaced from each o~her
and extending from said head toward said expansible portion and
merging into a sleeve-shaped shaft portion before said expansiblej
portion, said elongated neck having a cross-section which in a
middle region thereof has a shape of ellipse which merges into
~ circles 6aid head and said shaft portion, respectively, said
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1 legs being separated by a gap and having surfaces which face each
other, said gap having a dimension in a direction transverse to
an axis of the plug, which corresponds to a difference
between a major diameter and a minor diameter of said ellipse.
S When the plug is used in porous non-cavity building
materials, ~or example foam concrete, the plug is driven into a
dr.illed hole corresponding in diamete~ to the outside diameter
of the head and the shaft portion. As a result of the ellipse-
shaped enlargement, the legs of the elongated neck of the plug
are pressed together to the diameter of the drilled hole. Due to~
the size of the transverse dimension of the gap, this causes the ¦
surfaces defining the gap to contact each other in the middle
region o the legs. This narrowing of the gap caus~s a corre-
sponding displacement and wedging of the plug material in the
drilled hole as the fastening screw is screwed in, with the
result that a preliminary fastening occurs even before the ex-
pansible portion is reached.
The longitudinal grooves formed in the surfaces of the
plug define the gap between the two legs, which grooves start
from the longitudinal bore in the head portion and form a taper-
ing screw channel which serves to guide the screw and makes it
easier for the screw to cut into the material of the plug. The
elongated neck of the plug thus contributes to an improvement in
the anchoring, which is completed by screwing of the screw right
into the expansible portion of the plug. The expansibility of
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1 the elo ated neck due to the formation of two legs elso provides
additional securing against rotation, with the result that high
turning moments can be used when anchoring the actual expansible
portion.
S Due to its pressure-exerting ability in the region of
the elongated neck, the anchoring plug accordlng to the invention~
is also suitable for spaced mountings of the objects at
supporting structures since, because of the pressure exertion on the
object to be secured, the spacing which is set or results from
unevenness in the wall is fixed. The pressure forces acting on
the object to be secured are taken up by the anchoring plug by
the legs wedged in the drilled hole in the object being secured.
In a further embodiment of the invention, the fastening
screw may have a thread extending as far as its head. Due to the¦
extended thread, a thread connection is produced between the legs¦
o the elongated neck and the fastening screw. In addition, the
torque for screwing in the screw is reduced.
The legs of the elongated neck may have external
surfaces provided with locking tongues. Recesses may be provided
in said external surfaces, said tongues being retractable in said
recesses. The locking tongues prevent the legs from giving or
twisting in very porous building materials.
The expansible portion may be formed in the known
fashion by two spaced expansible legs extending between said
~ base po ion and said shaft portion.
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1 I The base portion may have a longitudlnal bore with an
internal thread or internal ribs. With -this type of
the expansible portion, this plug is suitable for all building
, materials, even for cavity bricks and cavity mountings. When
S I anchoring the plug in foam concrete using the aforedescribed
expansible portion,it has proved especially advantageous to
prepare the part of the drilled hole that is to accommodate the
l~ expansible portion using a special drilling device so that a
¦~ portion of the drilled hole is widened into a pear shape. The
li legs of the expansible portion are thus able to bend out~ard and
¦ to rest against the wall of the widened portion. Thls produces
considerably greater expansion than would be possible according
to the customary expansion principle which involves screwing a
fastening screw into a tapering internal drilled hole.
The novel features which are considered as character-
istic for the invention are set forth in particular in the ap-
pended claims. The invention itself, however, both as to its
construction and its method of operation, together with addition-
al objects and advantages thereof, will~be best understood from
the following description of specific embodiments when read in
onnection with the accompanying drawing.
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Figure 1 is an axial sectional view of the plastic
anchoring plug according to the invention, mountable in foam
concrete; and
S Figure 2 is an axial view of the plastic anchoring
plug of the invention, adapted for the spaced mounting of a
batten~
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The anchoring plug formed of plastic is shown in
j Figs. 1 and 2. The plug designated by reference numeral 1
includes an expansible portion 2 which is expanded and held in a
S I material in which the plug is inserted. Expansible portion 2 is
¦ suitable for all building materials. The plug illustrated in
¦ Fig. 1 is anchored in a porous non-cavity support material 3,
¦ such as foam concrete. As seen from Fig. 1 the mounting of the
¦¦ plug 1 in concrete 3 is flush. The expansible portion 2 of the
1¦ plug includes a base portion 4 which has a longitudinal bore with
~¦ internal ribs and two opposite legs 5 which extend upwardly from
¦¦ the base portion 4 and merge into a sleeve-like shank or shaft 6.
I¦ An elongated neck 8 is an extension of shank 6. This elongated
¦¦ neck 8 is formed by two legs 7 and is terminated in a head portion
. 11 which has a flange 9 which projects from the head portion 11
at right angles thereto. The head portion 11 also has external
ribs 10 which secure the same against rotation.
The shapes of cross-sections of the legs 5 c,f
the expansible portion 2 and legs 7 of ~e elongated neck 8, define in
~0 l¦ each case in their middle region an ellipse which changes into a
l circle in each direction toward the ends of the legs. The legs 7
'¦ of the elongated neck 8 and the legs 5 oE the expansible portion
2 are in each case separated from each other by a gap 12, the
~ dimension of which in the transverse direction corresponds to the
¦ difference between the major and the minor diameters of the
respective ellipse. As a result,the legs 5 and/or 7 can be pressed
together to the diameter of a drilled hole 13. The surfaces de-
fining the gap between the legs form a narrowed portion. When
the pluq l is placed in the drilled hole 13 a fastening screw 14
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1 is screwed through an object 15 to be secured in the concrete
into a longitudinal bore 16 provided in the plug 1. The narrow-
ing which results when two pairs of legs 5 and 7 are pressed to-
gether allows the legs to be displaced and expanded as the
1 fastening screw 14 is screwed in.
, Longitudinal grooves 17 are provided in the internal
il surfaces of legs 5, which define, on the one hand, a gap to
~¦ guide the screw 14 inserted in bore 16, and, on the other hand,
¦¦ these grooves facilitate cutting of the thread of the screw 14
¦ into the material of the plug 1. Once the screw 14 has
penetrated the sleeve-shaped shank portion 6, the screw 14
engages in the expansible portion 2 of the plug 1, formed by two
legs 5 while the base portion 4 acts as a nut for this screw.
,1 The axial tension which results due to the screwing-in of the
¦ screw 14, leads additionally to the twisting or bending of the
legs 5 of the expansible portion 2 outward. In order to facil-
I itate this bending of the legs 5 in the outward directions, the
I cross-section of portion 2 is weakened by the provision of a
transverse bore 18 extending in the plane of the lower gap 12 in
1 the region of the greatest enlargement of the legs 5.
A further weakening of the cross-section of portion 2
l is provided in the region where legs 5 join the base portion 4.
il This weakening in the cross-section is produced by two notches 19
¦¦ (Fig. 2) which extend at right angles to the plane of the lower
1ll gap 12.
I In order to obtain an increased expansion due to the
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1 ¦ bending of legs 5 outward even in xelatively strong foam concrete,
it is advantayeous to form a pear-shaped widened portion 20 of
the expansible portion 2 using a special drilling device. In
order to reliably secure the plug 1 against rotation during the
expansion operation, locking tongues 21 are formed on the legs 7
of the elongated neck 8. These tongues can be retracted into
recesses 22. Longitudinal grooves provided in the surfaces de-
1l fine the gap between the two legs, which grooves s-tart from the
¦l longitudinal bore in the head portion and form a tapering screw
~I channel which serves to guide the screw and makes it easier for
'I the screw to cut into the material of the plug.
Il With reference to Fig. 2 it will be seen that if a
spaced mounting of a batten 23 to a concrete structure is required
', the expansibility of the elongated neck 8 of the plug 1 is used
ii to fix the neck 8 of the plug 1 in the batten 23 which is to be
¦¦ fastened at a distance from structure 3. Once the plug 1 has
I¦ been anchoxed, the pressure forces acting on the batten 23 are
i! taken over by the plug,and the spacing, which has been set, is thus
j firmly fixed. In order to achieve a good connection between the
~ ll legs 7 of the elongated neck 8 and the fastening screw 14, the
thread of the screw 14 is extended as far as to its head 24.
¦ It will be understood that each of the elements describ-
ed above, or two or more together, may also find a useful appli-
~¦ cation in other types of anchoring plugs differing from the types
~5 " described above.
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l While the invention has heen illustrated and described
1 as embodied in an anchoring plug, it is not intended to be
! limited to the details shown, since various modifications and
¦¦ structural changes may be made without departing in any way from
S ¦¦ the spirit of the prevent invention.
¦¦ Without further analysis, the foregolng will so fully
I¦ reveal the gist of the present invention that others can, by ap-
¦¦ plying current knowledge, readily adapt it for various applica-
¦¦ tions without omitting features that, from the standpoint of
il prior art, fairly constitute essential characteristics of the
generic or specific aspects of this invention.
Il What is claimed as new and desired to be protected by
! Letters Patent is set forth in the appended claims.
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